SHAPED CHARGE FOR THE DESTRUCTION OF AMMUNITION UNDERWATER

Abstract: Ballistic disc ordnance disposal device adapted for better efficiency underwater has an air-filled extension cylinder (8) attached to the disc end of a shaped charge container (1). On detonation, the disc (7) is driven through the extension cylinder (8) and through a relatively thin end cover plate thereof (11). The extension cylinder provides an air-filled space that permits the disc (7) to gain sufficient speed to destroy say a limpet mine.

Description: SHAPED CHARGE FOR THE DESTRUCTION OF AMMUNITION UNDERWATER This invention relates to disposal apparatus for use underwater and more particularly but not exclusively to ballistic disc explosive ordnance disposal apparatus. The invention also relates to conversion apparatus for facilitating the operation underwater of an existing ballistic disc ordnance disposal apparatus. Explosive-driven ballistic disc devices have been used for the safe disposal of ordnance items in air. In one such device, a metal cylinder containing an explosive charge has a detonator at one end while the other end is closed by a cup-shaped copper disc. The cup-shaped profile of the disc protrudes into a matching depression in the explosive charge, i.e. a shaped charge is formed. In use, the disc is directed towards the item to be disposed of and the explosive charge detonated. This drives the disc to the item and the item is destroyed. Underwater, e.g.. to dispose of limpet mines and such, such devices are less effective. According to one aspect of the invention, there is provided disposal apparatus for use underwater, the apparatus comprising an enclosure which is sealed for excluding water therefrom and which contains explosive material and a disrupter member having one side adjacent to the explosive material and the other side facing but spaced from a disruptable wall portion of the enclosure for detonation of the explosive material to propel the disrupter member to and through the said wall portion and then impacting upon an item for disposal near which item the apparatus is positioned when ready for use. According to another aspect of the invention, there is provided apparatus for underwater operation of a ballistic disc ordnance disposal device, the apparatus comprising an elongated hollow member, a disruptable cover at one end of the hollow member, and attachment means for connecting the other end of the hollow member to a ballistic disc ordnance disposal device for the ballistic disc of the device to be exposed to the interior of the hollow member and to face but remain spaced from said one end thereof, and for the said interior of the hollow member to be sealed to exclude water therefrom. For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawing, the single figure of which is a sectional view of an explosive ballistic-disc disposal device which has been converted for better operation underwater. The disposal device comprises a hollow metal cylinder 1 containing a shaped explosive charge 2. The end 3 of the cylinder 1 is fitted with an electrical detonator 4. The other end 5 of the cylinder 1 is closed by a copper disc 6. The disc is cup-shaped to fit into a depression 7 at this end of the shaped charge 2. When used in air, the disposal device would be positioned with end 5 facing but spaced from the item to be destroyed. The explosive charge is then detonated and the disc is propelled onto the item. To make the device better suited for use underwater, there has been provided conversion apparatus including an aluminium extension cylinder 8 into one end of which there is fitted the end 5 of cylinder 1. The two cylinders are fixed and sealed together by epoxy adhesive 9. A clamp or other attachment device 10 is provided for fixing the device adjacent to an item to be destroyed. For example, one item might be a limpet mine on a ship's hull, and the device 10 should then be suitable for fixing the disposal device to that hull. The other end of the cylinder 8 is closed by a thin end plate 11 which might be less than 0.5mm thick for preference or could be even made of foil. The conversion apparatus also includes a water-tight sealing member 12 fitted to the detonator end of the cylinder 1. This member 11 comprises an aluminium plug 13, with plastic 0-ring seals 14 and grub-screw 15 to secure it. On detonation of charge 2, the disc 6 is driven forward through cylinder 8 and end cover plate 11 to impact the item to be disposed of. Cylinder 8 provides an air space in which disc 8 can gain sufficient speed to destroy the item. Instead of comprising a separate disposal device and conversion apparatus, the cylinders 1 and 8 could be made, say of plastics material, as an integral whole. The complete disposal apparatus could be incorporated into an underwater item of equipment or weapon for use as a self-destruct system.

Claims: CLAIMS 1. Disposal apparatus for use underwater, the apparatus comprising an enclosure which is sealed for excluding water therefrom and which contains explosive material and a disrupter member having one side adjacent to the explosive material and the other side facing but spaced from a disruptable wall portion of the enclosure for detonation of the explosive material to propel the disrupter member to and through the said wall portion and then impacting upon an item for disposal, near which item the apparatus is positioned when ready for use. 2. Apparatus according to claim 1, wherein the enclosure is elongate. 3. Apparatus according to claim 1 or 2, wherein the said wall portion is made of relatively thin material to ease emergence therethrough of the disrupter member. 4. Apparatus according to claim 1,2 or 3, wherein said disrupter member comprises sheet material and is positioned closely adjacent the explosive material, the member having a cup-shaped cross-sectional profile and protruding into a correspondingly shaped adjacent surface of the explosive material. 5. Apparatus according to any preceding claim, wherein the enclosure comprises a first hollow member filled with said explosive material and having one wall formed by said disrupter member, and a second hollow member having one wall formed by said disruptable wall portion and being connected to the first hollow member so that the disrupter member is exposed to the interior of the second hollow member and faces but is spaced from said disruptable wall portion. 6. Apparatus according to any preceding claim, wherein the enclosure is an elongate cylinder, the disrupter member is a copper disk and the disruptable wall portion is a relatively thin plate covering an end of the cylinder. 7. Disposal apparatus for use underwater substantially as hereinbefore described with reference to the accompanying drawings. 8. Apparatus for underwater operation of a ballistic disc ordnance disposal device, the apparatus comprising an elongated hollow member, a disruptable cover at one end of the hollow member, and attachment means for connecting the other end of the hollow member to a ballistic disc ordnance disposal device for the ballistic disc of the device to be exposed to the interior of the hollow member and to face but remain spaced from said one end thereof, and for the said interior of the hollow member to be sealed to exclude water therefrom.

Inventors: BAILEY DAVID, DENMAN TREVOR, BAILEY, DAVID, DENMAN, TREVOR
Applicants: BAESEMA LTD, BAILEY DAVID, DENMAN TREVOR, BAESEMA LIMITED, BAILEY, DAVID, DENMAN, TREVOR
Application year: 1994
Main classification: F42B3
IPC codes: F42B3